Although the term of 'formal semantic' might be used in a very general sense to refer to a whole set of different approaches to the study of meaning, it is usually employed nowadays with particular reference to a certain version of truth conditional semantics which originated in the investigation of specially constructed formal languages by logicians and has recently been applied to the investigation of natural languages.According to Tarski to know the meaning of certain sentence, it means to understand in what condition the sentence is true. For instance, the sentence 'snow is white', to know the meaning of that sentence we have to understand what condition existed that supports that sentence is true. There is a formula concerning this discussion:S is true if and if only PS refers to the sentence, and P refers to the condition which supports the S. from the preceding example we can say that snow is white is true and if only snow is white.In addition, the study of truth condition falls into two basic categories: the study of different types included in individual sentences: analytic and syntactic; and the study of different types of truth connections that hold between sentences; entailment and presupposition. .................................................................................................................See also: